Prior to this commit, running ob-watcher with
an onion-type message channel configured would result
in the bot attempting to connect to all the makers,
which is bad. This happened because the internal logic
of the onion message channel is that receivers of privmsgs
will be sent peer info from the directory, so that they can
immediately respond p2p if they succeed in outward connecting.
But for bots who do not intend to engage in a coinjoin interactive
protocol, like ob-watchers, this is absolutely not the desired outcome.
After this commit, a bot can specify mode "PASSIVE" in the call to
get_mchannels(), which results in the OnionMessageChannel object only
creating non-directory remote peer objects of type OnionPeerPassive,
instead of OnionPeer, which means they never try to connect to those
remote peers.
Adam Gibson
e915daef88